ABSTRACT
Objective:To observe the influence of emotional stress on the temporomandibular joint(TMJ) of SD rats. Methods:Standard animal model of emotional stress was created by emotion communication emergency box technique in 30 SD rats and foot-shocked in another 30. Control rats were 30 without treatment. The microstructure and ultrastructure of the disc surface, condylar surface and external pterygoid muscle were observed 1, 3 and 5 weeks after emotional stress treatment. Results:Obviously pathological changes were observed in the experimental animals, especially at 3 weeks, involving the fissures on the disc and condylar surface, the collagen fibers were disordered. Electron microscopy observation showed that condylar collagen was exposed. The mitochondria edema and vacuolar degeneration in the external pterygoid muscle were found.At 5 weeks, the condylar cartilage started to recover. Conclusion:Long term emotional stress may lead to pathological changes of the temporomandibular system. The changes can be partly recovered after a certain time of adaption of TMJ.